81001015 has 4 divisors (see below), whose sum is σ = 97201224. Its totient is φ = 64800808.

The previous prime is 81001007. The next prime is 81001021. The reversal of 81001015 is 51010018.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81001015 - 2³ = 81001007 is a prime.

It is a super-2 number, since 2×81001015² = 13122328862060450, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81001015.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8100097 + ... + 8100106.

It is an arithmetic number, because the mean of its divisors is an integer number (24300306).

Almost surely, 2^81001015 is an apocalyptic number.

81001015 is a deficient number, since it is larger than the sum of its proper divisors (16200209).

81001015 is a wasteful number, since it uses less digits than its factorization.

81001015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16200208.

The product of its (nonzero) digits is 40, while the sum is 16.

The square root of 81001015 is about 9000.0563887122. The cubic root of 81001015 is about 432.6766783480.

The spelling of 81001015 in words is "eighty-one million, one thousand, fifteen".